Experimental Design and Optimization: Application to a Grignard ReactionNaoual Bouzidi and Christel GozziThis 5-week project, which systematically investigates optimizing the synthesis of benzyl-1-cyclopentan-1-ol, constitutes an initiation into research methodology and experimental design to prepare the student-engineer for an industry internship. Other pedagogical goals include experience in synthetic techniques, obtaining reproducible yields, and using quantitative analysis methods.Bouzidi, Naoual; Gozzi, Christel. J. Chem. Educ.2008, 85, 1544.

Addition Reactions |

Alcohols |

Aldehydes / Ketones |

Chemometrics |

Gas Chromatography |

Organometallics |

Synthesis

Saying What You Mean: Teaching Mechanisms in Organic ChemistryJ. Brent FriesenWays to maintain clarity and consistency when teaching reaction mechanisms in organic chemistry include the use of balanced reaction equations, avoiding the use of shortcut notations, including key electrons and bonds in structural representations, and distinguishing between covalent and ionic bonds.Friesen, J. Brent. J. Chem. Educ.2008, 85, 1515.

The Chemistry of CoffeeWilliam F. ColemanThe paper Our Everyday Cup of Coffee: The Chemistry behind Its Magic by Marino Petracco provides a hearty blend of molecules for this month. The author deals with coffee at a number of different levels ranging from the economic and social to the still perplexing questions of flavor and aroma. The associated molecules demonstrate a range of structural features that students will benefit from examining in three dimensions.

Bioorganic Chemistry

Molecular Model of TubocurarineWilliam F. ColemanCurare, the Karib name for the plant from which this molecule is derived, is used in traditional South American medicine and hunting because it is a muscle relaxant. The three papers by Brunsvold and Ostercamp (1, 2, 3) provide us with an abundance of candidates for Featured Molecules this month. All of the major compounds highlighted in the papers, and many of the intermediates in the synthetic schemes, have been added to our collection. Students should note the structural similarities of the various barbiturate species and of the steroid-based compounds, as well as the interesting proto-cage structure of curare. Careful examination of the conformation of the alkyl groups in various of the molecules, when looked at as Newman projections, should convince students that their expectations about staggering substituents on adjacent tetrahedral-like carbon atoms are met in the computations. However, they should also be aware that recent work casts some doubt on the traditional explanation for that staggering (1). Charged species are presented in the collection in ionic form, without counterions (those are given in the papers), and all species except curare and atricurium besylate (molecule 40 in the third paper) were optimized at either HF/631-G(d) or B3LYP/631-G(d). The latter two molecules were optimized using HF/STO-3.